Automatic draft-regulating apparatus for boiler-furnaces.



116.824,824. PATTNTUU JULY s, 1906.

y A. SCHAPPUR. AUTOMATIC URATTRBGULATTNG APPARATUS PoR BUTLER TURNAGBS.

AIPLIOATION FILED JULY 20. 1904.

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PATENTBD JULY s, 1906.

A. SGHAFFER.

- AUTOMATIC DRAFT REGULATING APPARATUS POR BOILER FURNAGES.

APPLICATION FILED JULY 2o. 1904.

3 SHEETS-SEBET 2.

PATRNTRD JULY s, 1906.

A. SURATRRR. AUTOMATIC URATT RRRULATING APPARATUS .RoR RUILRR TUR NACES.

APPLIOATION FILED JULY 20. 1904.

3 SHEETS-SHEET 3.

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ADOLF SOHAFFER, OF VIENNA, AUSTRIA-HUNGARY.

AUTOMATIC DRAFT-REGULATING APPARATUS FOR BOlLEF-FURNACES.

Specification of Letters Patent.

Patented July 3, 1906.

Application le. July 2051904. Serial No. 217,315.

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Be it known that I, ADOLF SGHAFFER, a subject of the Emperor of Austria-Hungary, residing at Vienna, in the Province of Lower Austria and Empire of Austria -Hungary, have invented a new and useful Improve ment in Automatic Draft-Regulating Apparatus for Boiler-Furnaces, of which the following is a specification.

My invention relates to that class of ap paratus for automatically regulating the draft of furnaces wherein a piston-rod having two pistons is connected to the chimney damper or register, one piston working in a steam-cylinder and the other in the cylinder of a liquid cataract. In the intervalsbetween the stoking the damper and the two pistons are in a middle position. On opening the first fire-door the damper must descend to the lowermost position, which corresponds to the highest position of the pistons, and on closing the last fire-door the damper must attain its highest position and gradually descend to the middle position. Heretofore these operations have been controlled by steam-gear, which adds to the c'ost of the apparatus` Now this invention has for its object to replace the said steam-gear by simple and effective mechanism adapted to be operated by the fire-doors.

According to the invention a lifting-valve is provided for the admission of steam into the steam-cylinder, and this valve is connected with a weighted lever tending to open it and held in position by a pawl. A cam adapted to disengage this pawl is rotated by a mechanism operated by the fire-doors on their being opened and closed, and the saine mechanism rocks a shaft connected with cords which run to the cataract-valve and the pivoted stop limiting the stroke of the piston-rod.

In the annexed sheets of drawings, Figure 1 is a sectional elevation of the draft-regulating apparatus, the damper being drawn to a smaller scale. Fig. 2 is an elevation of the iire-doors and the mechanism operated by them drawn to a smaller scale than Fig. 1. Fig..3 is a similar view as Fig. 2, one firedoor being shown open. Figs. 4 and 5 are sectional top views of the crank connected with the fire-door and the cam secured to the endwise-movable rod to be reciprocated. Figs. 6 and 7 are front and side elevations, respectively, drawn to a larger scale, of the mechanism operated by the fire-doors and adapted to disengage the pawl of the weighted starting-lever.

As will be seenfrom Fig. 1, the damper 1 is connected to the piston-rod 2 by means of a wire rope 3 passing over rollers, the said piston-rod being adapted to have its length adjusted by means of a hand-wheel 4, made integral with a swivel-joint 5 and a nut 6. The piston-rod 2 carries a piston 7, sliding in a steam-cylinder 8, and a piston 9, inserted into the cylinder 10 of a liquid cataract. Before each stoking operation'the damper 1 is in the middle position, (indicated by the broken lines,) by which the fire is maintained fresh and which corresponds -to the middle position of the pistons 7 and 9. (Not shown in the drawings.) In order to adjust this middle position to the particular require ments of a plant at any time, the piston-rod 2 is provided with an adjustable stopecollar 11, which acts in conjunction with an abutment-roller l2, mounted upon a lever-arm 13, which is held in upright position by a spring 14. If now the first fire-door l5 is opened for purposes of stoking, the crank 16, which is fitted to the hinge-bolt of the door and whose crank pin 17 engages a loopshaped cam 18, secured to an endwise-movable rod 19, pushes to the right this endwisemovable rod, which rests in guides above-the fire-doors. This movement is illustrated by Figs. 3, 4, and 5.

By means of the two-armed lever20 the endwise movement of the rod 19 is transmitted in an opposite direction to a rod 21, jointed to a lever-arm 22, which is secured to a shaft 23, the bearings of which are formed in cheeks 24, screwed to the steam-cylinder 8. To the nave of the pawl-lever 33, secured to 4the shaft 23 and referred to below, are secured the ends of two wire cords 25 and 26, the former one running over a roller to the lever 1 3, which carries the abutment-roller 1 2, and the latter one to the valve 27 of the cataract. The angular movement of the shaft 23 has for its effect that both wire cords are wound up and that consequently the leverarm 13 is turned away from the piston-rod 2 and the valve 27 opened. The damper 1 can consequently drop and raise the pistons 7 and 9 from the middle positions to their highest positions. (Indicated in dotted lines, Fig. l.) The steam and condensed water contained in the cylinder 8 pass through the narrow bore 28 of the piston 7 and flow out through a pipe screwed into the screw- IOO IIO

threaded perforation 29 in the side of the cylinder 3, while in the cylinder 10 the liquid above the piston 9 rapidly passes through the open valve 27 and the passage 30 into the portion of the cylinder beneath 'the piston.

The shaft 23 also carries a ratchet-wheel 31, loosely mounted upon the shaft and having alternately long and short teeth engaged. by a pawl 32, which is carried by a pawl-lever 33, secured to the shaft 23. The angular movement of the lever-arm 22, caused by the 'lirstlire-door 15 being opened, has for its effect that the pawl 32 slides backward the breadth of a tooth. Afterward when the door 15 is closed the crank-pin 17 of the crank 16 (see Fig. 5) pushes the eye-shaped cam 1S to the left, which has for its effect that the rod 19 also slides in this direction and imparts movement in the opposite direction to the rod 21. By the consequent movement of the lever-arm 22, the shaft 23, and the pawl-lever 33 the ratchet-'wheel 31 is turned an angle corresponding to the breadth of a tooth. i

Above the ratchet-wheel 31 a bell-crank lever 34 is pivoted between the cheeks 24, in which the shaft 23 is journaled. A screw 35, screwed into a lateral projection of the horizontal arm of the bell-crank lever 34, rests under the action of the weight of the lever u pon a pawl 36, mounted on the pivot of the lever and engaging the ratchet-wheel 31. The upright arm of the bell-crank lever 34 is provided with a projecting' nose 37, against which bears the cross-p in 38 of the forked end of a two-armed lever-39. This lever is pivoted at 40 to a link 41, `iointed to the valvebox 42, which is screwed to the steam-cylinder 8 and connected with. a steam-pipe. (Not shown in the drawings.) The freeend of the lever 39 carries an adjustable weight 43, while a point of the other lever-arm near the pivot has ointed to it the stem of the steamadmission valve 44.

On the first fire-door 15 being' opened. and closed a short tooth of the ratchet-wheel 31 passes under the pa'wl 36, and the angular movement which thereby is imparted to the bell-crank lever 34 .is not suffi-cient :for disengaging the nose 37 from the cross-pin 38.

In the drawings it is supposed that the furnace is provided with two lire-doors, so that the second one, 45, is at the same time the last one. On this last fire-door 45 beingl opened the rods 19 and 21 and the pawl 32 perform similar movements as on the opening of the first fire-door 15. Afterward when the last fire-door 45 is closed the pawl 32 moves forward and causes a long tooth ojl' the ratchet-wheel 31 to pass under the pawl 36, upon which rests the horizontal arm of the bell-crank lever 34. Thereby the nose 37 is sufficiently swung backward as to get clear of the cross-pin 38 of the forked end of the lever 39, and consequently the weight 43 can drop.

This has for its eHect that the valve 44 is lifted and that steam enters the cylinder S, pushing the piston 7 downward,I while at the same time the ]iiston 9 of the liquid cataract descends in its cylinder 10, causing the liquid to pass through the passage 30 and the valve 27 into the upper end of the cylinder. t ith this descending of the two pistons coincides the rising of the damper 1 to its uppermost poftion.

At the moment when the two pistons 7 and 9 nearly reach the end of their downward stroke a collar 46, 'fixed to the piston-.rod 2, contacts with the forked end of the lever 39, and thereby closes the steam admission valve 44. The steam shut up in the cylinder 3 gradually cools and also escapes, thus permitting the damper 1 to drop and to raise the pistons 7 and 9. The steam and condensed water from the cylinder S :flow through the narrow perforation 28 of the piston 7 and are exhausted. through a pipe screwed into the hole 29` while the liquid contained in the cylind er 10 is obliged to flow through the narrow passage 46, which can be adjusted by means of the needle-valve 47. Thus the damper 1 is caused to descend slowly and its downward movement ceases at the moment when the stop-collar 1.1 reaches the abutmentroller 12. The pot 4S serves for filling liquid into the cataract-cylinder 10.

1t will be readily understood that numerous other mechanisms may be devised for imparting endwise movements to the rod 19 under the action of the opening and closing movements of thefire-doors. Thus, for instance, a weight or spring maybe provided for pushing the rod in one direction and an abutment and eccentric for moving it in the opposite direction. 1f more than two iredoors be present, the middle ones are not geared with the rod 19.

The ratchet-wheel 31 performs at the same time the office of a cam and therefore has teeth of different lengths; but it is obvious that a separate cam may be used and ratchet mechanism for driving this cam.

Vhat I claim, and desire to secure by Letters Patent of the United States, is-

1. In an automatic draft-regulating apparatus, the combination of a piston-rod, a pivoted spring-controlled stop for the pistonrod, a rotatable drum, a cord connecting the pivoted stop with said drum, a plurality of fire-doors, and mechanism connecting the lire-doors with said drum whereby the opening and closing of the fire-doors will cause partial rotation of' the drum in opposite directions respectively.

2. In an automatic draft-regulating apparatus, the combination with iire-doors, of a rotatable drum, a cataract-valve, a cord connecting the valve with the drum, and mechanism connecting the lire-doors and drum whereby upon the 'lire-doors being opened IIO ISO

and closed, the drum is partly rotated in opposite directions respectively.

3. In an automatic draft-regulating apparatus, the combination with fire-doors, a steam-cylinder, an admission-valve for the cylinder, a weighted lever connected with the valve tendingl to normally open it, a pawl arranged to normally prevent the movement of the lever to open the valve, a ratchet-wheel having cam-teeth arranged to engage and operate the pawl, a pawl-lever arranged to engage and operate the ratchet-wheel, a rod arranged to be reciprocated by the opening and closing of the fire-doors, and connections between the rod and pawl-lever arranged to oscillate the pawl and lever on the reciprocation of the rod.

il. In an automatic draft-regulating apparatus, the combination of a damper, a pair oi' ire-doors, means for maintaining the damper in a partly-open position when the nre-doors are closed, means to allow the damper to move to a closed position upon the opening of one of the rire-doors, means for moving the damper to a fully-open position upon the closing of the second door, and means for thereupon returning the damper to its partly-open position 'by a retarded motion.

5. In an automatic draft-regulating apparatus, the combination of a vertically-movable daniper, a casing provided with tandem cylinders, a piston in each cylinder, a pistonrod to which said pistons are secured, a cable connecting the piston-rod with the damper, an admission-valve at one end of one of the cylinders, an outlet at the other end of such tons, a pawl member arranged to engage said lever to retain the valve closed, a lug on the piston-rod, a spring-lever arranged to engage the lug and retain the piston-rod to hold the damper in apartly-open position, a windingdruin having two cords connected thereto,

one of such cords being connected with the.

spring-lever, the other one of the cylinders having a port connecting its extremities with a valve arranged therein, said second cable being attached to said valve, an arm connected with the winding-drum, a reciprocatingbar operated by the opening and closing of the fire-doors and connected with said arm whereby the operation of the fire-doors will oscillate the winding-drum, a ratchet-wheel loose on the shaft of the winding-drum and having its alternate teeth provided with enlarged cam-surfaces arranged to engage and trip the said pawl member connected with the valve-lever, and a pawl pivotally connected with the winding-drum shaft and engaging said ratchet-teeth to advance the ratchet-wheel on the reciprocation of said rod and arm.

In witness whereof I have signed this speciication in presence of two witnesses.

ADOLF SCHAFFER. 

